1. Field of the Invention
The present invention relates to a fixing apparatus and an image forming apparatus including the same.
2. Related Art
There are image forming apparatuses such as a copy machine, a printer, a facsimile machine and a multi-functional printer as apparatuses for forming (printing) an image on paper of a transfer object. Such an image forming apparatus forms an image on the paper by sequentially performing: an exposure step that forms an electrostatic latent image on a surface of a photoreceptor drum as the image supporting unit by irradiating the surface of the photoreceptor drum with laser light; a development step that develops an image by depositing toner on the electrostatic latent image formed on the surface of the photoreceptor drum; an image transfer step that transfers a toner image formed of the toner deposited on the surface of the photoreceptor drum to the paper; and a fixation step that fixes the toner image transferred to the paper onto the paper.
In the fixation step among the abovementioned steps, the toner needs to be fused in order to fix the toner image transferred to the paper. As a fixing apparatus performing the fixation step, a fixing apparatus has been conventionally used, which includes a heating rotator such as a heating roller, a pressurizing rotator such as a pressurizing roller and a heating mechanism for heating the heating rotator. Such a fixing apparatus pushes the pressurizing rotator against the heating rotator in order to form a fixing nip between the heating rotator and the pressurizing rotator and maintains a predetermined nip pressure in the fixing nip. The paper is fed into the fixing nip, so that the toner transferred to the paper is fused, pressurized and fixed onto the paper.
Generally, the fixing apparatus is provided with a separating member for separating a sheet of paper having passed through the fixing nip from a peripheral surface of the heating rotator. Introduction of such a separating member prevents an occurrence of a paper jam. On the other hand, it is likely that the heating rotator suffers from damage, such as streaks on a surface of the heating rotator, which are created by a tip of the separating member that comes in contact with the peripheral surface of the heating rotator. Under this circumstance, a technique is proposed, which regulates (limits) movement of the tip of the separating member toward the peripheral surface of the heating rotator, such that a minuscule gap is maintained between the tip of the separating member and the peripheral surface of the heating rotator.
However, since the minuscule gap is maintained between the tip of the separating member and the peripheral surface of the heating rotator in the abovementioned fixing apparatus, it is likely that an edge of a sheet of paper having passed through the fixing nip enters the gap. When the edge of the sheet of paper enters the gap, the sheet of paper tends to stick firmly to the peripheral surface of the heating rotator. In such a case, it is difficult to troubleshoot jamming of the paper stuck to the peripheral surface of the heating rotator.
Therefore, a fixing apparatus is in high demand, which enables removing of a sheet of paper stuck to the peripheral surface of the heating rotator.